Hello,
i think it is not exactly a bug but not implemented or provided by now but i think you should be able to reanimate with a defibrilator when someone is dead. This would promote teamplay. Otherwise teamplay is nearly impossible because when one player dies you have to cross sometimes hughe distances to be reunited. Besides i think, bringing someone back from unconsciousness with a defibrilator is not so realistic because it could kill him..
EDIT: maby it wouldnt kill him. probably test it with a handcuffed stranger in dayz?